IFNB1 and infection: There were no significant differences observed in viral burden, BAL protein secretion, IFN-β- and IFN-λ-related gene expression, epithelial-related gene expression, and weight loss at day 21 after infection between the H1N1 + intravenous PBS and H1N1 + intravenous MBV groups (P > 0.05; fig.